/*
   Copyright 2007 Marco Slot (marco.slot@gmail.com)

   Licensed under the Apache License, Version 2.0 (the "License");
   you may not use this file except in compliance with the License.
   You may obtain a copy of the License at

       http://www.apache.org/licenses/LICENSE-2.0

   Unless required by applicable law or agreed to in writing, software
   distributed under the License is distributed on an "AS IS" BASIS,
   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   See the License for the specific language governing permissions and
   limitations under the License.
 */
package nl.marcoslot.lib.calc;

import nl.marcoslot.lib.io.ParseException;

/**
 * This class can be attached to an expression parser to control
 * evaluation of variables.
 *
 * @author Marco Slot
 */
public interface VariableController {
    /**
     * Gets the value associated with a name.
     * 
     * @param name 
     *      The name of the variable
     * @throws nl.marcoslot.lib.io.ParseException 
     *      If the variable name is invalid
     * @return 
     *      The value associated with the name
     */
    public Value getVariable(String name) throws ParseException;
}
